Spinning frame, preferably ring spinning frame

ABSTRACT

A spinning frame of the type having a main drafting zone through which two fiber bands move in spaced parallel relation for subsequent twisting into a single yarn is provided with a first pair of rollers located at the entrance to the main drafting zone, a second pair of rollers located at the exit of the main drafting zone, a pair of endless leather tapes extending about a roller in each of the first and second pair of rollers, and a third pair of rollers for delivering two fiber bands from the main drafting zone to a suitable twisting device. A first pair of fiber band guides is located adjacent to and upstream of the first pair of rollers relative to the direction of travel of the fiber band, a second pair of fiber band guides is located intermediate the second and third pairs of rollers and a pair of coaxially spaced apart annular ring slots are provided in the outer surface of one of the first pair of rollers with the first and second pairs of guides being aligned with the ring slots for maintaining the fiber bands in alignment with the ring slots.

The present invention is directed to spinning frames of the type havingmain drafting means through which two fiber bands move in spacedparallel relation for subsequent twisting by suitable twisting meanswherein one of the entrance rollers of the main drafting means overwhich an endless leather tape passes is provided with a pair of axiallyspaced apart parallel annular ring slots.

The uniformity of the yarn produced by such spinning frames often leavesa lot to be desired. It is therefore a task of the invention to improvethe uniformity of yarn produced on such spinning frames.

As a consequence of the two ring slots of the upper roller located onthe entry side of the main drafting zone and encompassed by an upperapron, the length of the main drafting zone of the drawing system can beadjusted to somewhat less than the length of the longest fiber of thefiber bands without any danger of ripping the fiber; thereby thedrafting work of the drawing system and thus the uniformity of the yarnproduced from both fiber bands by means of their being twisted togethercan be improved. The fiber band guides of the drawing system ensure aprecise feed of the fiber bands through the drawing system into theposition necessary for the two ring slots of the upper roller.

Despite the two ring slots of the upper roller of the entry roller pairof the main drafting zone, the two fiber bands are sufficiently clampedon their way through this pair of entry rollers to enable the maindrafting--and in the case where there is a pre-drafting zone, also thepre-drafting--to be precisely carried out. Practically speaking, onlythe relatively low proportion of fibers which are longer than the maindrafting zone distance are pulled through the clamping surface of theentry roller pair more rapidly than the transport speed of the entryroller pair of the main drafting zone, without tearing these long fibersthanks to the ring slots of the upper entry roller. The width of bothring slots of the upper roller of the entry roller pair of the maindrafting zone can easily be designed such that fiber bands of varyingfiber composition and differing numbers can be drawn. In general it isefficient to arrange things such that the width of each of the two ringslots of this upper roller roughly corresponds to the width of the fiberband under it in the clamping gap of this entry roller pair of the maindrafting zone. If fiber bands of widely differing numbers are to be spunon the spinning frame, one can adjust the width of the ring slots ofthis upper roller according to the width of the fiber bands to beprocessed on the machine and the maximum weight/length unit. In such acase it is also possible to have two or more sets of upper entry rollersof main drafting zone with ring slots of various widths, whichcorrespond to the various number areas of the fiber bands to beprocessed, and which can also be interchanged if necessary.

The upper apron ca correspond to the usual drawing systems, particularlythose of traditional worsted yarn spinning frames, and the upper rollerit encompasses can have a normal elastic covering in which, however,ring slots are located. It is preferable that the main drafting zonealso have a lower leather tape. For spinning frames with pre-draftingzones, two fiber band guides can also be advantageous in thepre-drafting zone, whereby the vertical median lengthwise planes of itsfiber band guide channels roughly match the vertical median lengthwiseplanes of the two ring slots of the upper entry roller of the maindrafting zone. The upper entry roller of the main drafting zone can alsoform the upper exit roller of the pre-drafting zone.

The two fiber band guides of each pair of fiber tape guides canadvantageously be connected to each other, for example to form asingle-piece double fiber band guide.

The two fiber band guides located in the main drafting zone can best beheld merely by placing them on the two fiber bands so that they arecarried by same. On the other hand, it is useful to arrange all thefiber band guides for the main drafting zone such that they are heldimmovable during operation.

All fiber band guides can be formed such that their fiber band channelsform open rills for the simple feeding of the fiber bands, and they canalso be formed such that they become narrow like a funnel for purposesof concentrating the fiber bands in the directin of fiber band movement.Yet it is also possible to have at least one pair of fiber band guideswith hole-shaped fiber band channels, if one wishes to accept thetime-consuming threading of the fiber bands into these holes.

The fiber bands can preferably be combed wool, but fiber tapes of otherfinite-length fibers can also be be spun, preferably of fibers with arelatively long average fiber length.

The uniformity of the yarn produced from both fiber tapes when twistedtogether can be further improved if one guides it through a rotatingthread guide located at a distance from the exit of the drawing systemand into a fiber balloon formed by same; the reason is that the rotationimparted to the yarn propagates itself more efficiently in the areabetween the drawing system and this thread guide. Preferably, thisthread guide can rotate with about the same rpm as the spindle, etc., towhich the yarn flows. For example, the rotating thread guide can beshaped as in DE-OS No. 23 43 776.

When the spinning frame is designed as a ring spinning frame, a threadguide is located at a relatively small distance above the spindle ofeach spinning location; such thread guides are preferably the rotatingthread guides mentioned above, or could also be non-rotating. It ispreferable that the smallest internal diameter of this thread guide is 2mm if possible, or less, since by this means the otherwise easilyoccurring formation of a weak fiber balloon between the union point ofthe two individual fibers and this thread guide, which worsens theuniformity of the yarn, can be avoided.

A design example is illustrated in the drawing:

FIG. 1 shows a cross-sectional front view of a spinning location of aring spinning frame which is not drawn in further detail;

FIG. 2 shows a partially-cross-sectional top view for a drawing systemwith two spinning locations of a ring spinning frame located next toeach other, as in FIG. 1, whereby certain portions are cut away for abetter view.

FIG. 3 shows a side view of a double fiber tape guide of the draftingsystem according to FIG. 2.

The spinning location 9 depicted in cross-section in FIG. 1, one of manysuch spinning locations of a ring spinning frame, has a delivery rollerpair 12, consisting of an upper roller 10 and a lower roller 11, of adrawing system 13 which is not illustrated in further detail in FIG. 1.The drawing system illustrated in greater detail in FIG. 2 has two suchspinning locations 9 next to one another. For a better view into thedrawing system 13, the upper apron 14 in FIG. 2 at the left spinninglocation 9 is illustrated in cutaway view, and the upper delivery roller10 is broken away. For each spinning location 9 the drawing system 13has a pre-drafting zone 15 and a main drafting zone 16. In thepre-drafting field 15 only low drafting or only coordination drafting iscarried out on the two fiber bands 19, 20 which are to be drawn, and inthe main drafting field 16 these two fiber bands 19, 20 are then draftedwith a high drafting force and then go from the delivery roller pair 12(still untwisted) and to a union point 21, where they are then twistedtogether to form a finished yarn 7, which is then (as in FIG. 1) routedthrough a thread guide 22 coaxial with a rotating spindle 23, through atraveller 26 moving around a spinning ring 24 to the spindle 23, whereit is wound onto a bobbin on the spindle 23 into a winding 25. The twofiber bands located between the delivery roller pair 12 and the unionpoint 21 are designated as individual fibers 19' and 20'.

The drawing system portion which relates to an individual spinninglocation 9 is described below.

Through each portion of the drawing system, two fiber bands 19, 20running in spaced parallel relation to each other, are drafted at thesame time. These two fiber bands 19, 20 can preferably come from asingle feeding spool, upon which they were simultaneously wound.

The pre-drafting field 15 is bordered on the one side by a feed rollerpair consisting of a lower roller 29 and an upper roller 30 whichpresses against it, and on the exit side by a center roller pairconsisting of a center lower roller 31 and an upper roller 32 surroundedby the endless upper apron 14. The upper apron 14 is carried by aguiding cage 33 which also guides the other upper apron 14 of thisdrawing system 13, and is then routed around by the forward edge 60 ofthe cage half 61 assigned to it, with little clearance, and then lies onthe outer surface of the center upper roller 32 at an angle of somewhatmore than 180°. This center upper roller pair 31,32 also forms the entryroller pair of the main drafting zone 16, whose exit roller pair formsthe delivery roller pair 12.

The upper rollers 30, 32, and 10 of the drawing system which are pressedagainst the corresponding lower rollers 29, 31, and 11 as in FIG. 2 areat any given time rotatable about common shafts 35, 36, and 37respectively, which in turn is carried by a normal upper roller carrier(not illustrated) and spring loaded.

In addition, lower aprons of the usual kind are located around thecenter lower roller 31 and a routing rail 39, and if need be they aretensioned by a tension roller, not illustrated; while these tapes arenot visible, they are located in FIG. 2 directly below the upper apron14, such that the two fiber bands 19,20 in the main drawing zone 16 areguided between the upper apron and lower apron.

The three lower rollers 29, 31, and 11 of this drawing system 13 can, asis normal, be formed via long roller elements which run along theappropriate side of the ring spinning frame (not further illustrated),and which can be the same as all the drawing systems of this side of themachine.

The upper roller 32 surrounded by the upper apron 14 has the usualelastic cot of plastic or the equivalent, but in which there are twoflat ring slots 40, 40'--a departure from the normal technique in thisinvention--which are right-angular, constant, and have a consistentlylarge cross section, and which are coaxial with the rotating axis of theupper roller 32 and covered by the upper apron 14.

On a fixed carrier brace 42 which runs along the appropriate side of theframe, a double fiber band guide 43 is located a short distance fromeach gathering roller pair 29, 30 and has two convex arc-shaped (inrelation to lengthwise direction in FIG. 3) channel-type guide grooves44, 44' serving to guide the two fiber bands 19, 20. This double fiberband guide 43 consists of a single-piece injection molded component andis affixed to the stationary carrier brace 42. Its two grooves 44,44'become narrower in a funnel-like fashion in the direction of fibermovement, in order to concentrate the two fiber bands 19, 20. Thesegrooves 44, 44' are open to the bottom.

In each main drawing zone 16 there is also a double fiber band guide 45,which consists of two fiber band guides 47 held together by a stiffbrace 46 and which are open at the bottom. They narrow in the directionof fiber band movement, and each have a groove open toward the bottom toguide the two fiber bands 19,20. This double fiber band guide 45 isplaced upon the two fiber bands 19, 20 from above and is carried bythese, and thus pressed against at least one of the two rollers 10, 11of the delivery roller pair 12.

In each pre-drafting zone 15 are likewise two fiber band guides 49 forthe two fiber bands 19, 20 which run through it. They are mounted on oneof the fixed rails 50 which run along the spinning frame and each ofwhich has a funnel-shaped groove (in relation to the direction of fibermovement) open at the top, to guide the fiber bands 19, 20. The mediandistance of the grooves of these two fiber band guides 49 (which formthe fiber band guide channels) from each other, as well as the mediandistance of the two grooves 44, 44' which also form fiber band guidechannels for the double fiber band guide 43, and also the mediandistance of the two grooves of the fiber band guide 47 which likewiseform fiber band guide channels for the fiber band guide 47 of the doublefiber band guide 45, are all equally large, and correspond to the medianclearance of the two ring slots 40, 40' of the appropriate draftingsystem upper roller 32. The vertical lengthwise median planes of thegrooves of the fiber band guides 43, 49, and 45 guiding the same fiberband 19 and 20 respectively, roughly overlap one another as well as thevertical lengthwise median plane of the ring slot 40, 40' of the upperroller 32 above the appropriate fiber band 19 or 20. The width of thering slot 40, 40' is approximately the same size as or somewhat largerthan the width of the fiber band which is located under it and movesthrough the clamping gap to the center roller pair 31, 32. The extent ofthe main drafting zone 16 is adjusted to be a bit smaller than themaximum fiber length of the fibers in the fiber bands to be drawn 19,20. This is done to improve the uniformity of the spun yarn 7 throughimproved drafting. The long fibers, if they are in contact with thedelivery roller pair 12, can be pulled out from the clamping gap of thecenter roller pair 31, 32 without tearing thanks to the grooves 40, 40'on the upper roller 32.

We claim:
 1. In a spinning frame of the type having main drafting meansthrough which two fiber bands move in spaced apart relation forsubsequent twisting by suitable twisting means comprising a first pairof rollers located at the entrance to said main drafting means, a secondpair of rollers located at the exit of said main drafting means fordelivering the two fiber bands from said main drafting means to saidtwisting means, and an endless apron extending about the upper roller ofsaid first pair of rollers, the improvement comprising a first pair offiber band guides located upstream of said first pair of rollersrelative to the direction of movement of said bands, a second pair offiber band guides located intermediate said first and second pairs ofrollers and a pair of coaxial spaced apart annular ring slots providedin the outer surface of the upper roller of said first pair of rollerswith said first and second pairs of guides being substantially alignedwith said ring slots for maintaining said fiber bands in alignment withsaid ring slots.
 2. A spinning frame as set forth in claim 1 furthercomprising pre-drafting means located upstream of said main draftingmeans comprising a third pair of rollers upstream of said first pair ofrollers, and a third pair of fiber band guides located upstream of saidpre-drafting means substantially in alignment with said first and secondpairs of fiber band guides and said pair of ring slots, respectively,said first pair of fiber band guides being located intermediate saidfirst and third pairs of rollers.
 3. A spinning frame as set forth inclaim 1 wherein said second pair of fiber band guides is comprised oftwo interconnected fiber band guides each of which is provided with adownwardly open groove for receiving a respective fiber band wherebyeach fiber band guide is supported directly on the respective fiberband.
 4. A spinning frame as set forth in claim 1 wherein each fiberband guide includes a groove which becomes narrower in the direction offiber band movement for the purpose of concentrating the fiber bandpassing therethrough.
 5. A spinning frame as set forth in claim 1wherein each of said fiber band guides is provided with an open groovefor guiding a fiber band to facilitate the initial feeding of the fiberbands through the guides.
 6. A spinning frame as set forth in claim 1wherein the width of each of said ring slots is at least equal to thewidth of the fiber band passing over the associated apron.
 7. A spinningframe as set forth in claim 1 wherein said twisting means is comprisedof a spindle having ring and traveller means associated therewith andfurther comprising a yarn guide having an aperture disposed in coaxialrelation to said spindle with the diameter of said yarn guide meanssufficiently small relative to the twisted yarn so as to preventballooning of the yarn upstream of said yarn guide.